Copolymers which contain perfluoroalkyl groups (RF) and the use of these copolymers for the treatment of fiber materials are known. This is evident, for example, from FR-A 2 213 333, DE-A 27 02 632 and EP-A 234 724.
The copolymers known from the prior art and aqueous dispersions thereof have disadvantages as well as advantages. This is true particularly if they are to serve for the treatment of fiber materials made of polyolefins, especially polypropylene. This is because it has been found that relatively high temperatures have to be applied in order to achieve the desired effects on the fiber materials. These effects are, for example, oil-/water-repellent properties and alcohol-repellent properties. Articles made of polypropylene which are to be used in the medical sector are often required to effectively repel low molecular weight alcohols such as isopropanol. For other fields of use, such as, for example, in the automobile sector, on the other hand, it is not the repellent effect toward alcohols that is of central importance, but an oil-repellent effect. This is also true for fiber materials made of other polymers, such as, for example, polyester and polyester/cellulose mixtures. In order to achieve such alcohol-repellent and/or oil-/water-repellent properties, the fiber materials treated with RF copolymers have to be subjected to elevated temperatures. In the case of RF copolymers known from the prior art, temperatures of more than 130 to 140° C. are often required for this. These copolymers are consequently unsuitable, or suitable only to a limited extent, for fiber materials which are damaged at the specified temperatures. Particularly in the case of fiber materials made of polypropylene, there is the risk that, following treatment with known RF copolymers and heating to more than 130° C., the polypropylene material is damaged.